Project Summary/Abstract Substance abuse accounts for 5-6% of the US population yet only 20% of individuals with substance use disorders (SUDs) utilize treatment services given the significant treatment access barriers (e.g., stigma; economic, time, and transportation constraints; lack of access to qualified providers; challenges navigating complex treatment systems; low perceived utility). Consumer applications (apps) and automated conversational agents (CAs) may reduce or eliminate common yet significant barriers to traditional SUDs treatment. CAs can deliver a coach or sponsor-like experience and yet do not require human implementation assistance for in-the-moment treatment delivery. Thus, their scale potential is unconstrained and immediate; CAs engage millions of users instantaneously. Being non-human-based also reduces perceived stigma. The conversational, text-based interface increases engagement, a feat non-relational apps have failed to achieve consistently. Woebot, a CA instantaneously available 24 hours per day, 7 days per week, ?checks in? with users. Using conversational tones, it encourages mood tracking and delivers general psychoeducation as well as tailored empathy, cognitive behavior therapy (CBT)-based behavior change tools, and behavioral pattern insight. Woebot?s app-based platform and user-centered design philosophy makes it an optimal modality for SUDs treatment delivery; it offers immediate, evidence-based tailored support in the patient?s peak moment of craving. An RCT demonstrated that Woebot had statistically and clinically significant reductions in depression compared to a control group, along with best in class app-engagement rates (mean=12 interactions in 14 days). Woebot does not currently offer a SUDs program, although 63% of current users expressed interest in said content. Woebot?s current, substantial reach as a consumer app, preliminary data indicating its high user engagement plus efficacy to treat a psychological condition, posies it as an ideal platform for a SUDs-focused, tailored, and immediately scalable digital therapeutic. Thus, this application proposes to: (1) develop and pilot an evidence-based, substance abuse content specific for a Woebot-delivered digital therapeutic for individuals with sub- and full syndrome substance use disorders (Woebot-SUDs; phase I); (2) engage with the FDA regarding W-SUDs potential for FDA approval as well as (3) investigate W-SUDs efficacy compared to a SCC in an appropriately powered RCT (phase II).